Inspired by a tweet by @levelsio by the same title, here's a list of things I wouldn't build myself in 2020 and some suggestions worth building, and all the reasons why:
COVID stats tracker - information is not enough for behaviourial change. Not when general trust with mainstream media is low. Persuading the population to wear masks, keep a safe distance, stay home and don't gather in large groups will need different tactics other than the intellect/cognitive. Perhaps sharing emotive stories will be a better tracker.
Todo apps - generalized todo apps are the chairs in the design industry. Every designer wants their own spin on the chair, so does every developer. It's saturated and boring. But perhaps todo apps can work in super niche work situations where tracking the tasks is important, like say a factory, or distributing meds at a hospital.
Remote job boards - COVID basically threw the world into remote work, and remote work job boards are flowering like wild weeds. Probably better off not making a general one, unless you belong in an industry or vocation where there's a gap, like say digital is not common yet, open roles are still spread by word of mouth, and/or matching candidates to employers is hard.
Free icon pack - designers, just don't. Besides icons, also trending are free packs of illustrations and Figma/Sketch templates. Just. Don't. Unless it's part of a larger marketing strategy, free design packs are so commoditized they are almost worthless. Some exceptions could be (again) super niche use cases. Like say illustrations for healthcare/medical apps. But you probably really need to understand the industry to come up with something original and in demand.
What else wouldn't you build in 2020? What would you build instead?